The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent that work is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Today, many mobile devices (smartphones, tablet personal computers, etc.) are capable of determining their location using one or more of various locating techniques. For example, some mobile devices are equipped with a Global Positioning System (GPS) chip to determine the latitude, longitude, and elevation of the mobile device based on signals received from several GPS satellites. Some mobile devices are instead (or additionally) capable of determining their location using signals from fixed or semi-fixed terrestrial elements having known locations, such as fixed cellular infrastructure elements (e.g., cellular tower base stations), WiFi access points (APs) or “hotspots,” etc. These locating techniques based on fixed or semi-fixed terrestrial elements may be useful if other techniques such as GPS are unavailable. For example, signals from WiFi APs may be used to locate a mobile device when the mobile device is indoors and unable to receive a GPS signal, or does not include a GPS chip.
Relying on fixed or semi-fixed terrestrial elements such as WiFi APs to locate a mobile device suffers from various drawbacks. For example, locating techniques may become less accurate when relying on APs that have been relocated or shut down, and may fail to take advantage of relatively new APs for which no location is yet known to a locating system.